W5DXS - Heart Of Texas DX Society

HOTDXS WORKBENCH

KC5LDO Pi Network Tuner

The pi network tuner is a valuable asset for anyone's station. It has been around
for many years and its popularity comes from being able to match a wide variety
of antennas and feed lines. Harmonic suppression is a huge plus.

The construction is not difficult since the variable capacitors do not have to be
insulated from the chassis. Broadcast style capacitors work well up to 100 watts.
The coil can be air wound or wound on a low loss form. I used a 2 inch diameter
ceramic form with 34 turns tapped every three turns.

I have not used the tuner below 80 meter, so you may have to add turns for 160
meter coverage. It's best to mount the coil at least 2 inches from the cabinet.

There are many combinations of turns and settings. Use the least amount of coil
turns as needed with maximum capacity. Simply tune for maximum received signal
and you'll be close enough for transmitting. A minor touch up may be needed.